<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #father{
            width: 400px;
            height: 400px;
            background-color: red;
        }
        #son{
            width: 200px;
            height: 200px;
            background-color: blue;
        }
    </style>
</head>
<body>
    <div id="father">
        <div id="son"></div>
    </div>
    <script>
        var father = document.getElementById("father");
        var son = document.getElementById("son");
        father.addEventListener("click",function(){
            alert("father click");
        })
        son.addEventListener("click",function(){
            alert("son click")
        })
    </script>
</body>
</html>